William Balfour is in custody for killing the Oscar winner's mother, brother and nephew.

The October slayings of Jennifer Hudson's family has resulted in the arrest of her brother-in-law.

William Balfour, who had been held on suspicion of a parole violation, was taken back into custody on Monday, Dec. 1 in Illinois' Cook County for the October killings of the Oscar winner's mother, brother and nephew, report news sources.

Balfour, 27, is the estranged husband of the "American Idol" finalist's sister Julia Hudson. It is believed that on Oct. 24, she had called Balfour to discuss a financial matter. While she was at work, he then allegedly went to her home where he shot and killed Hudson's mother Donell Donerson, 57, and brother Jason Judson, 29.

Julia Hudson's 7-year-old son, Julian King, went missing from the home, and his body, dead of gunshot wounds, was found three days later in the backseat of an abandoned SUV.

After the bodies of the victims were first discovered, Balfour was immediately taken in as a suspect in the killings but was transferred to a state facility for a parole violation for a 1999 conviction for attempted murder. He has yet to be charged.

Hudson, who won an Oscar for her supporting role in "Dreamgirls" and currently stars in "The Secret Life of Bees," also had offered a $100,000 reward for the return of her nephew. She became engaged last month on her 27th birthday to David Otunga, better known as "Punk" from the second season of the reality dating show "I Love New York."